You can ink and position your background stamps as mentioned but, you can also roll the brayer over it to ensure a nice crisp stamped image.
Technique using BG stamps:
Ink any BG stamp with whatever dye ink you want- rubber side up. Press a solid shaped stamp such as- flower from love without end or bold blossoms into the inked rubber side. Then stamp flower onto paper (you have the pattern from the large BG stamp on the stamp). Gives a new life to some of the sets you may be bored with.